The primary goal is to develop a noninvasive, objective method for measuring suprathreshold properties of human hearing. The objective method requires that electrical potentials be evoked from the brains of normal-hearing adults. Suprathreshold properties, rather than absolute threshold, are targeted because of their proven relevance to the processing of complex sounds such as speech. The properties selected for study include: frequency resolution, temporal acuity, frequency and intensity discrimination, and binaural interaction. To Validate the objective (physiological) method, behavioral (psychophysical) responses are obtained from the same listeners using comparable stimulus conditions and adaptive procedures. Each property is tested with at least two stimulus configurations as an additional validity check. With the objective method, (1) persons who are either unwilling or unable to respond behaviorally can be tested;. (2) cognitive factors (e.g., learning, memory, attention, etc.) that may cause inconsistent behavioral responses can be controlled; and (3) more stimulus conditions and/or clients can be evaluated in a given period of time. The objective method may ultimately be used to diagnosis and monitor hearing loss and to provide information regarding the selection of appropriate amplification systems.